The present invention relates to an apparatus and method of cleaning nozzle and an apparatus of processing a substrate.
In a photolithographic process for use in manufacturing semiconductor devices, resist is coated on a wafer and the resultant wafer is pattern-exposed to light and then developed. In a developing process, a developing solution is supplied so as to spread over an entire surface of the wafer. To describe more specifically, the developing solution is mounted on a stationary wafer, and then, a latent image is developed by use of natural convection of the developing solution. After the development, the wafer is rotated at a high speed to remove the developing solution from the wafer, rinsed and dried.
As the developing solution, for example, an aqueous tetramethylammonium hydroxide (TMAH) solution is used. When the aqueous TMAH solution is attached to a tip portion of the developing nozzle, dried and oxidized, a carbonate compound is produced. The produced carbonate compound may possibly exfoliate off from the tip portion of the developing nozzle and attach to a wafer as a contaminant.
When the developing nozzle is not used for a long time or when the specs (recipe) of the process is changed, an operator manually cleans the tip portion of the developing nozzle. To render the developing nozzle ready to use after the cleaning, a trial output of the developing solution from the nozzle, called "dummy running", is required. However, these serially performed manual operations are quite complicated and becomes a burden of the operator.